1. Field of the Invention
This invention relates to a process for producing a roller for an electrophotography, a process for producing a regenerated roller for an electrophotography, and a process for making a conductive roller low in electric resistance.
2. Description of the Related Art
In image forming apparatus that utilizes an electrophotographic system, a conductive roller having a conductive mandrel and a conductive surface layer which contains a resin and a carbon black dispersed in the resin is used as a developing roller, a charging roller, a transfer roller, a fixing roller, a cleaning roller or the like. In recent years, with progress of achieving much more high-performance of electrophotographic image forming apparatuses, it has become required to control the electric resistance of the conductive roller more precisely. In general, where a conducting agent is dispersed in a resin to make the roller conductive, its electric resistance tends to vary depending on the state of dispersion of the conducting agent.
Meanwhile, the conductive roller has a tendency of becoming high in electric resistance as a result of its continuous energization in an electrophotographic apparatus. As one of the causes thereof, such a tendency is said to be due to the fact that the state of dispersion of the conducting agent in a surface layer changes depending on the potential difference applied between the conductive mandrel and any other member coming into contact therewith. Now, from the viewpoint of lessening any environmental loads, it has become necessary to make technical development for the reuse of such conductive rollers having changed in electric resistance with their use.
Japanese Patent Application Laid-open No. 2002-40759 discloses a conductive roller for an electrophotography which has a mandrel made of a metal and provided on the periphery thereof with an elastic conductive layer is subjected to corona discharge treatment on its surface so as to make a developer adhere uniformly to the roller surface.